Question

我正在尝试在API调用后设置$currentUser，但我一直收到错误：

[default] 
Type 'Observable<{}>' is not assignable to type 'Observable<User>'.
  Type '{}' is not assignable to type 'User'.
    Property 'username' is missing in type '{}'.

我抛出错误的组件如下所示：

import {Component, state} from '@angular/core';
import { Observable } from "rxjs";

import { User } from '../../../../models/user';
import { Store } from '@ngrx/store';
import { AppState } from '../../../../reducers';
import {UserService} from "../../../../services/user.service";

@Component({
  selector: 'user-center',
  templateUrl: 'user-center.component.html',
  styleUrls: ['user-center.component.scss']
})
export class UserCenter {
  $currentUser: Observable<User>;
  userService: UserService;
  constructor(
    userService: UserService,
    public store: Store<AppState>
  ) {
    this.userService = userService;
    this.$currentUser = this.store.select('user');
  }

  ngOnInit() {
    this.userService.initialise();
  }
}

我的效果看起来像这样::

import { Injectable } from '@angular/core';
import { Effect, StateUpdates, toPayload } from '@ngrx/effects';
import { Observable } from 'rxjs/Observable';

import { AppState } from '../reducers';
import { UserService } from '../services/user.service';
import { UserActions } from "../actions/UserActions";

@Injectable()
export class UserEffects {
  constructor(
    private updates$: StateUpdates<AppState>,
    private userService: UserService,
    private userActions: UserActions,
  ) {}


  @Effect() CurrentUser$ = this.updates$
    .whenAction('INIT_USER')
    .switchMap(() => this.userService.getUser()
      .map(user => this.userActions.setCurrentUser(user))
      .catch(() => Observable.of({ type: 'GET_USER_FAILED' })
      ));
}

Answer 1

您应该更改构造函数并将依赖关系设置为Store var list = JsonConvert.SerializeObject(Yourmodel, Formatting.None, new JsonSerializerSettings() { ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore }); return list;。或者你真的需要它作为public store: Store<User>吗？应使用泛型src/operator/select.ts自动设置类型：

Store<AppState>

或者，抛出错误是因为您将constructor( userService: UserService, public store: Store<User> ) { this.userService = userService; this.$currentUser = this.store.select('user'); }定义为：

$currentUser

因此您可以在将数据分配到$currentUser: Observable<User>;时使用type assertion in TypeScript：

this.$currentUser

获取错误输入'Observable＆lt; {}＆gt;'不能分配给'Observable <user>'类型。当试图使用@ ngrx / store的store.select（）时

1 个答案: